Aged ACSR conductors. I. Testing procedures for conductors and line items

Field and laboratory tests of aluminum conductor steel reinforced (ACSR) conductors and related line items from many of Ontario Hydro´s older transmission lines are described. A nondestructive corrosion detector was modified for live line measurement of the loss of galvanizing from the steel cores of the ACSR conductors. Samples of conductors tested in the field have also undergone laboratory metallurgical investigation, and tests of fatigue, tensile strength, torsional ductility and electrical performance. Extensive environmental studies have identified corrosion products of ACSR conductors, the atmospheric factors responsible for corrosion, and the mechanisms by which corrosion takes place. It is concluded that the corrosion detector serves as a useful indicator of impending end of conductor life while the torsional ductility tests serve as a more precise condition indicator and can provide a guide for scheduling conductor replacement